Improved yarn handling sucker gun



June 8, 1963 w. c. ASHBY ET AL 3,094,262

IMPROVED YARN HANDLING SUCKER 'GUN Filed NOV. 25, 1960 2 Sheets-Sheet 1Q E I;

fig

l iii 6 u WILLIAM CRO PER ASHBY 3 WILLIAM WALLAR BUNTING, JRI

Lg ROBERT MEAGHER THOMAS LARSON NELS KENNETH GILBERT SWA E J1me 1963v w.c. ASHBY ETAL 3,094,262

IMPROVED YARN HANfiLING SUCKER GUN Filed Nov. 25, 1960 FIG.3

2 Sheets-Sheet 2 FIG-4a 62 INVENTORS 59 wn. M CROPPER ASHBY WIL MwALLaERRBuNTlNG, JR.

0 60 1B3BERT MEAG OMAS LARSON NRELSON ENNETH 2 55M SWAYNE United StatesPatent Ofiice 3,094,262 Patented June 18, 1963 IMPROVED YARN HANDLINGSUCKER GUN William Cropper Ashby and William Wallar Bunting, Jr.,

Wilmington, Del., Robert Meagher, Wallingford, Pa.,

and Thomas Larson Nelson, Newark, and Kenneth Gilbert Swayne, Hockessin,Del., assignors to E. I. du Pont de Nemours and Company, Wilmington,Del., a corporation of Delaware Filed Nov. 25, 1960, Ser. No. 71,662 8Claims. (Cl. 226-97) This invention relates to the field of textileyarn-ham dling or manipulating devices and, in particular, to a portabledevice capable of picking up a running length of yarn and maintainingthe yarn under tension until it can be transferred to a yarn take-up orother winding device.

In handling threads of either natural or synthetic origin, it isfrequently desirable that the thread be collected temporarily by anauxiliary device rather than by the regular collecting or windupapparatus. For example, US Patent No. 2,667,964, to Miller describessuch a conventional yarn-handling device. This invention is consideredto be an improvement over the Miller device.

It is an object of this invention to provide an improved efiicientyarn-handling device capable of quickly picking up a running length ofyarn and maintaining the yarn under high tension until it has beentransferred to a yarn take-up or winding device.

It is a further object of this invention to supply an improvedyarn-handling device capable of providing a high inlet air velocity forvery rapid picking up of a running length of yarn and thereafterproducing and maintaining a desired high level tension on the yarn untilthe yarn line has been transferred to a suitable take-up device.

A still further object is to provide such an improved portableyarn-handling device incorporating these features capable ofexpeditiously transferring a running length of yarn under suitabletension between points separated by considerable distances.

Another object is the provision of an improved yarnhandling device whichcan apply suflicient tension to handle yarns moving at extremelyhigh-speeds, e.g., 2,000 to 3,000 yards per minute without forming anyappreciable slack or allowing tensionin the yarn to drop a significantamount.

Yet another object is the provision of such a yarnhandling device whichcan handle effectively multi-filamen-t yarns to which a finish has beenapplied and which are wet and tend to stick together and act like amonofilament.

Yet another object is the provision of an improved handling device whichis simple in construction yet efficient and reliable in operation. Otherobjects will become apparent from the description hereinafter.

The aforementioned objects are accomplished by apparatus embodyingfeatures of this invention, which apparatus provides basically aportable yarn-handling device comprising a primary-air inlet tube; asecondary-air inlet tube; an air outlet tube; the outlet slideablymounted to form with the secondary-air inlet tube a variable annulus;the secondary-air inlet tube and the outlet tube forming a passagewayfor the yarn through the device the improvement comprising thecombination of an annulus or orifice configuration with an improvedoutlet tube configuration and also a turbulence generating means mountedon the end of the secondary-air inlet tube and extending into the outlettube.

In the drawings, FIGURES 1a and lb are longitudinal cross-sectionalpartial views of inlet and outlet 2 portions respectively of :a yarnhandling device embodying features of the present invention.

FIGURE 2 is a partial longitudinal cross-sectional view of the preferredturbulence generating element taken along the line 2-2 of FIGURE 1.

FIGURE 3 is a longitudinal cross-sectional view of a modifiedyarn-handling device of this invention illustrating the composite outlettube construction.

FIGURE 4A and B are respectively a partial longitudinal cross-sectionalview and an end view of the inner end of the auxiliary air and yarninlet tube showing a.

modified form of the turbulence generating means.

FIGURES 5, 5a, 5b and 5c illustrate in longitudinal cross-section aparticular auxiliary air inlet restriction device for use withyarn-handling devices of this invention in the closed position andtransverse cross sections taken through the device, along the lines5a-5a, 5b5b and 5c-5c respectively.

FIGURE 6 is a longitudinal cross-sectional view of the device of FIGURE5 showing it in the open position.

As shown in FIGURE 1, the main body of the device is formed by primaryair inlet tube 2. Outlet tube 4 is slideably mounted inside tube 2. Thesecondary-air inlet tube 6 is mounted at one end in the primary-airinlet tube 2 in such a manner that its longitudinal or axial positionwith relation to the outlet tube 4 can be adjusted to restrict or openthe orifice 32 formed between the inner ends of tubes 4 and 6. Housingunit 8 is mounted at the yarn inlet end of the primary-air inlet tube 2and functions as the tip of the device. A bore in the housing unit 8 islocated on the same axis as the bore of the secondaryair inlet tube 6and functions as an extension of the inlet tube. Mounted in the end ofthe housing 8 is a wearresistant bushing 10 which can be easily replacedwhen Worn. Mounted on the end of the secondary-air inlet tube -6 is aprojecting element 12, which extends into the bore of the outlet tube 4and into the flow of main inlet air moving through the orifice 32. Onthe yarn outlet end of the outlet tube 4 there is mounted a fixed piston14 and a fixed piston 16, with piston 16 having a larger transversecross-sectional area than piston 14. A housing 18 is attached to thedownstream or end of the primary-air inlet tube 2 and contains piston 16and a mount for an adjusting screw 20. In the space between the pistons14 and 16, the housing 18 is vented to the atmosphere by a large passage50. The cover on the housing 18 is provided with a small vent passage 51communicating with the side of the piston opposite from that of ventpassage 50. Tube 22 supplies the primary air to over p.s.i.g.) to thedevice at housing unit 26. Valve 24, mounted in housing 26 and operatedby push button 28, or other suitable device, controls the air supply topiston '16 via an auxiliary tube 36. In operation primary air underpressure is supplied to tube 22 and passes through passageway 30, formedby the interior surface of primary-air inlet tube 2 and the exteriorsurface of outlet tube 4, into the annular orifice 32 formed between theinner ends of outlet tube 4 and the secondary-air inlet tube 6 andthence down the bore of the outlet tube 4 to the yarn and air dischargeend of the device which may be connected to any suitable yarn collectionapparatus (not shown). The high pressure air in passage 30 also exerts apressure on piston 14 urging it toward the yarn discharge end of thedevice and thus urging the yarn tube 4 and the piston 16 in the samedirection until the latter abuts adjusting screw 20; when the yarn tube4 is thus pulled away from the yarn inlet tube 6, the annular orifice 32is said to be in the open position (shown) as hereinafter discussed.When push button 28 is depressed, valve 24 admits air under pressure tothe right side of piston 16 (the area of which is appreciably largerthan that of piston 14) thus causing pistons 14 and 16 as well as theyarn tube to move to the left, in effect making the cross-sectional areaof the annular orifice 32 smaller (not shown); in this situation theannular orifice 32 is said to be in the restricted condition. When valve24 admits high pressure air to the space to the right of piston 16, aminute amount of air will escape to the atmosphere through hole 51;however, the pressure on piston -16 remains ample to overcome thepressure on piston 14. The function of hole 51 is to permit the highpressure air to bleed down, after valve 24 is closed, thus permittingpiston 14 to move yarn tube 4 to the right.

In the restricted condition of the annular orifice 32, the pressure inthe zone adjacent the orifice will be reduced by virtue of Bernoullisprinciple which, in brief, states that minimum pressure occurs whenkinetic energy is maximum. Thus the high velocity air through theorifice 32 creates a low pressure at the inner end of the secondary-airinlet tube 6 and causes secondary air to flow into the bore of housing 8and the bore of secondary air inlet tube 6 from the surroundingatmosphere. In the open condition of orifice 32 the configuration of theorifice is in effect a converging-diverging nozzle capable of producingsupersonic flow conditions at the supply pressures used. The bore of theoutlet tube 4 is substantially constant, but diverging slightly tomaintain nearly constant air velocity in the tube and accommodate growthof the boundary layer along the wall surface. The characteristics ofthis tube constitute an important aspect of the invention. This tubeserves to prevent a substantial decrease in the kinetic energy of themoving air, a continuing pressure drop is maintained along its length.In order to function properly, it has been found that at the highpressures of 90# p.s.i.g. and above required for the desired high yarnof velocities and tensions, the total included angle of this bore mustbe between about minutes and about 1 with the preferred angle of from to45'. For supply pressures higher than about 90# p.s.i.g., the optimumangle of divergence is somewhat larger.

In operation, with the orifice 32 in its restricted condition, thesecondary-air which is caused to flow from the atmosphere into andthrough housing 8 and secondary-air inlet tube 6 causes a yarn line 34,when placed close to bushing 10, to be drawn into the inlet tube anddown the outlet tube. The combined action of the flow of thesecondary-air and the fiow of the primary air through the outlet tube 4maintains the yarn moving although under a low tension.

Once the yarn is moving through the device it is highly desirable toapply forces such that the yarn will be brought to a high tension levelin as short a period of time as possible; to this end, the annularorifice 32 is brought to its open condition, by releasing push button28, whereupon high velocity air in the tube 4 will exert tension on theyam 34. Under this condition the pressure in the region of the annularorifice 32 is higher; i.e., suction is at a minimum. When the yarn 34has been brought to an appreciable tension level, the device may bemanually transported to bring the yarn into proximity with otherapparatus for the purpose of transferring the yarn to that apparatus.

When the annular orifice 32 is in its open condition the pressure in theregion of the orifice is super-atmospheric; therefore, a flow of airexists through tube 6 countercurrent to the direction of yarn movement.If an adequate supply of high pressure primary air is available in theregion of the annular orifice 32, the rate of air flow and hence the airvelocity in the outlet tube 4 will be unaffected by the existence of anycountercurrent flow in tube 6 hence such flow is not deleterious to theoperation of the device. However, in terms of air consumption, moreeconomical operation may be achieved if such flow is minimized; this maybe accomplished by the use of an adjustable restriction in the tube 6or, preferably, in the bore of the housing 8 by means of the apparatussuch as that shown in FIGURES 5, 5A, 5B, 5C and 6. FIG- URES 5A, 5B, 5Cand 6 show a tube 59, intended for use on the free end of the housingunit 8, which tube 59 contains two generally cylindrical members 60 and61. The members 60 and 61 are cut on a matching bias or miter and areprovided, respectively, with longitudinal V shaped slots 62 and 63 suchthat when the mitered ends of the members 60 and 61 are in abutment theV slots are apart. The member 60 is firmly secured to the inside of thetube 59 while the member 61 is free to slide axially inside the tubebeing backstopped, however, by the internal flange 59a as shown inFIGURE 6. When the annular orifice of the device is in the restrictedposition, atmospheric pressure or suction caused by flow of air throughthe device will push the member 61 against the flange 59a thus opening acomparatively large flow passage through the Vs 62, 63 (FIGURE 6); whenthe annular orifice of the device of this invention is in the openposition, super-atmospheric pressure inside the device will cause airflow to be reversed in the air and yarn inlet tube to push member 61into abutment with member 60 (FIG- URE 5A) thus efiectively reducing theflow area to the adjoining roots of the Vs 62, 63 as shown in FIGURE 5Aand reducing leakage back through the air and yarn inlet tube. Thedevice of FIGURES 5 and 6 is thus automatic.

Adjustments for obtaining optimum performance of the device are madesequentially. The annular orifice 32 is first placed in the restricted,or yarn string-up, condition whereupon the inlet tube 6 is axiallyadjusted, by means of the screw threads provided, until the velocity ofthe secondary inlet air reaches a maximum. In this condition, of course,the pressure at the inner end of the inlet tube 6 is sub-atmospheric.When the best setting has been achieved, the inlet tube 6 is locked inposition by means of the jam nut that is provided. Next, the device isshifted to the open condition (by release of push button 28) whereuponthe yarn tube 4 is adjusted axially, by means of the screw 20, until amaximum yarn tension condition is reached with a moving threadline.Thereafter, it is only necessary to manipulate the push button 28 tocause the yarn tube to shift to either of the desired positions.

The tension that can be applied to the yarn can be expressed by theNewton equation where C is a characteristic drag coefiicient, D is themass density, V is the relative velocity, and A is the area of contact.It will be seen from this equation that in handling a specificmulti-filament yarn, four factors affect the tension applied to a yarn;length of the yarn exposed to the high velocity air, velocity of the airstream, effective surface area of contact of air stream and yarn, andthe mass density of the fluid.

In the improved yarn-handling device embodying the principles of thepresent invention, during the maximum tension condition the air flow isbelieved to reach supersonic conditions and is maintained in the veryhigh velocity condition substantially throughout the length of theoutlet tube to give a maximum average air stream velocity and maintainit in contact with the yarn for a maximum distance. Also, it has beenfound, and an example will be given below, that the insertion of a smalltab element 12 or some other device to create an extremely turbulentcondition or a very high degree of agitation in the fluid stream justbeyond the annulus 32 greatly increases the tension on the yarn 34 whenall other conditions are kept the same. The greatly agitated fluidstream is characterized by the existence of a high degree of turbulence,severe velocity gradients, eddies, vortices, and the like and may becharacterized further by rotation of the fluid stream in whole or inpart. The operation and function of this tab element is not fullyunderstood. However, it is believed that the turbulence generator or tabelement may cause the 'multi-filament yarn to oscillate or vibratelaterally and thus to open up and somewhat entangle and thus present asubstantially larger effective area for the air to operate upon. This isquite important with wet yarns moving at a high velocity and which haveusually a tendency to adhere together and act like a monofilament yarn.It is important that the yarn guiding surfaces within the bushing andthe auxiliary air and yarn inlet tube be arranged to direct the yarninto the vicinity of the tab in the orifice.

In one application of the principles of this invention to ayarn-handling device a yarn string-up device with the followingdimensions was run with and without a metal tab. Outlet tube 4: length18", divergent angle 30 minutes, ID. of bore .250", radius of curvatureforming the CD. of annulus 32, .03" to .09"; secondary-air inlet tube:bore .140", total included angle on tip forming the ID. of annulus 32,40; metal tab: length .25", width .093", thickness .032.

Table I Tension, grams Primary Air Flow in s.c.f.rn. (Supply pressure at90 p. s. 1.) Without With Tab Tab This test was run with 70-34 polyesterfiber yarn with a finish running at 3,000 yards per minute.

The following demonstrates the critical aspects of the diverging angleof the bore of the outlet tube 4. A device, with a metal tab 12, asdescribed above, was used, all conditions except this angle being heldconstant.

Total included Yarn tension,

A modified form of turbulence generating means is shown in FIGURES 4Aand 4B. Suitable turbulence levels can be created by the use of anauxiliary air and yarn inlet tube 140 having its inner end provided withscalloped portions 144 circumferentially spaced around the edge. Asshown, all but one of the scalloped portions are turned outwardly, theremaining one is turned inwardly to obtain the desired results.

It will be seen that a novel improved arrangement for a yarn-handlingdevice has been provided. The preferred yarn-handling device of thisinvention utilizes in the maximum tension condition a supersonic airflow and also includes a small turbulence generating structure whichcontributes to the greatly improved tension levels which are needed inthe yarn at high yarn speeds. In addition, a convenient and rapid meanshas been provided to shift the gun between the maximum auxiliary airinlet velocity and the maximum tension conditions of operation.

A modified yarn-handling device is illustrated in FIGURE 3 which shows adesirable composite outlet tube construction. The composite outlet tube4' comprises an outer sleeve or casing 4a formed of metal, and an innerliner member 4b formed of suitable moldable or castable plastic materialsuch as, for example, an epoxy resin. If desired the plastic materialmay be suit ably reinforced, e.g., with glass fibers, and the outercasing eliminated. The construction of the inner mem ber of such cast ormolded plastic material provides a simple, economical way to form thedesired nozzle configuration and tapered outlet tube contour withoutexpensive machining operations. In addition, such a liner providesoptimum wear and frictional characteristics for the yarn and air passingtherethrough.

In compliance with the patent statutes a preferred embodiment of thisinvention has been described but it is to be understood that variousmodifications could be made without departing from the spirit of theinvention or the scope of the appended claims:

We claim:

1. A yarn-handling device comprising an air inlet tube, an air outlettube having an outer exit end and an inner end, a passageway betweensaid inlet and said outlet tubes, the outer exit end of said outlet tubeprovided with an elongated section of substantially constantcross-sectional area, an auxiliary air and yarn inlet tube having anouter end and an inner end, one of said air outlet and auxiliary air andyarn inlet tubes mounted for movement relative to the other, said innerend of said air and yarn inlet tube mounted to form in cooperation withthe inner end of said outlet tube, a variable annular orifice, saidorifice forming, in one condition of its variation and in cooperationwith said elongated section, a convergingdiverging nozzle, said devicefurther comprising a conduit connecting said air inlet tube to a sourceof high pressure air, the pressure of the air in the inlet tube duringoperation of the device, the contour of said nozzle, and the elongatedsection each cooperating to produce supersonic air flow in said nozzleand maintain extremely high air flow velocities substantially throughoutthe elongated section of said outlet tube, and manually actuatablepneumatic means to rapidly and selectively vary the longitudinalrelative positions of said outlet tube and said auxiliary inlet tube inorder to vary the annular orifice, the improved device furthercomprising a bafile means cooperating with said orifice for creating azone of great agitation in the air flowing through said nozzle and saidoutlet tube.

2. The improved device of claim 1 which further comprises a variablemeans cooperating with said auxiliary air and yarn inlet tube forrestricting the flow of air through said auxiliary air and yarn inlettube.

3. The improved device of claim 1 in which said means for creating azone of agitation in the flowing air comprises a plurality of scallopsformed in the inner end of said auxiliary air and yarn inlet tube.

4. The improved device of claim 2 in which said variable means comprisesfirst and second transversely positioned abutment elements positioned insaid auxiliary air and yarn inlet tube, each abutment element providedwith an axially extending yarn guiding groove diametrically opposed tothe groove of said other element, said elements mounted in said tube forrelative movement with respect to each other in an axial directionbetween a first arrangement in which said elements are spaced a givendistance apart and a second arrangement in which said elements aresubstantially in abutting relationship such that the diametricallyopposed grooves form a restricted orifice permitting passage of the yarnalong the length of both elements.

5. An improved yarn-handling device comprising in combination an airinlet tube, an air and yarn outlet tube having an inlet end and anoutlet end, a passageway connecting said inlet and outlet tubes, theoutlet tube provided between its ends with an elongated section ofsubstantially constant cross-sectional area, an auxiliary air and yarninlet tube mounted in alignment with said outlet tube, and incooperative association with, and for relative motion with respect tothe inlet end of said outlet tube to form a variable annular orifice,the outlet end of said auxiliary inlet tube and the inlet end of saidoutlet tube cooperating to form in one given condition of its variationa converging-diverging nozzle arrangement, a conduit member connectingsaid air inlet tube to a source of high pressure air, the pressure ofthe air in the inlet tube during operation of the device, theconfiguration of the converging-diverging nozzle arrangement, and theelongated section of the outlet tube each cooperating to producesupersonic air flow at the nozzle arrangement and maintain extremelyhigh air flow velocities substantially throughout the elongated sectionof the outlet tube to exert a high tension on a yarn line entering theauxiliary inlet tube and passing through the device to the exit end ofthe outlet tube, the improved device further comprising a turbulencegenerating element projecting into the variable orifice, said elementhaving an effective crosssectional area of very small magnitude withrespect to the cross-sectional area of the orifice.

6. The improved device of claim 5 which further comprises a manuallyactuatable pneumatic means for rapidly and selectively varying therelative longitudinal positions of the inlet end of the outlet tube andthe outlet end of the auxiliary inlet tube to vary the annular orificeopening between a maximum opening maximum yarn tension position and aminimum opening maximum auxiliary air velocity position.

7. The improved device of claim 6 in which said elongated portion ofsaid outlet tube is provided with a very gradually increasing innerdiameter defined by side walls which represent slightly divergingconical surface along the direction of air flow having an included angleof from about fifteen to forty-five minutes in order to substantiallymaintain the extremely high air flow velocity undiminished and a verygradual pressure drop along its length.

8. A yarn-handling device comprising an air inlet tube, an air outlettube having an outer exit end and an inner end, a passageway betweensaid inlet and said outlet tubes, the outer exit end of said outlet tubeprovided with an elongated section of substantially constantcrosssectional area, an auxiliary air and yarn inlet tube having anouter end and an inner end, one of said air outlet and auxiliary air andyarn inlet tubes movable relative to the other, the inner end of saidinlet tube mounted to form in cooperation with the inner end of saidoutlet tube, and in further cooperation with said elongated section, avariable annular orifice, said orifice forming in one condition of itsvariation a converging-diverging nozzle, said device further comprisinga conduit connecting said air inlet tube to a source of high pressureair, the pressure of the air in the inlet tube during operation of thedevice, the contour of said nozzle, and the elongated section eachcooperating to produce supersonic air flow in said nozzle and maintainextremely high air flow velocitiessubstantially throughout the elongatedsection of said outlet tube, and reciprocating means operativelyconnected to said outlet tube to rapidly and selectively vary thelongitudinal relative positions of said outlet tube and said auxiliaryinlet tube in two directions in order to rapidly vary the annularorifice.

References Cited in the file of this patent UNITED STATES PATENTS1,118,552 Honiss Nov. 24, 1914 2,667,964 Miller Feb. 2, 1954 2,731,262Morrow Jan. 17, 1956 2,971,686 Paulsen 'Feb. 14, 1961 FOREIGN PATENTS842,762 Great Britain July 27, 1960

1. A YARN-HANDLING DEVICE COMPRISING AN AIR INLET TUBE, AN AIR OUTLETTUBE HAVING AN OUTER EXIT END AND AN INNER END, A PASSAGEWAY BETWEENSAID INLET AND SAID OUTLET TUBES, THE OUTER EXIT END OF SAID OUTLET TUBEPROVIDED WITH AN ELONGATED SECTION OF SUBSTANTIALLY CONSTANTCROSS-SECTIONAL AREA, AN AUXILIARY AIR AND YARN INLET TUBE HAVING ANOUTER END AND AN INNER END, ONE OF SAID AIR OUTLET AND AUXILIARY AIR ANDYARN INLET TUBES MOUNTED FOR MOVEMENT RELATIVE TO THE OTHER, SAID INNEREND OF SAID AIR AND YARN INLET TUBE MOUNTED TO FORM IN COOPERATION WITHTHE INNER END OF SAID OUTLET TUBE, A VARIABLE ANNULAR ORIFICE, SAIDORIFICE FORMING, IN ONE CONDITION OF ITS VARIATION AND IN COOPERATIONWITH SAID ELONGATED SECTION, A CONVERGINGDIVERGING NOZZLE, SAID DEVICEFURTHER COMPRISING A CONDUIT CONNECTING SAID AIR INLET TUBE TO A SOURCEOF HIGH PRESSURE AIR, THE PRESSURE OF THE AIR IN THE INLET TUBE DURINGOPERATION OF THE DEVICE, THE CONTOUR OF SAID NOZZLE, AND THE ELONGATEDSECTION EACH COOPERATING TO PRODUCE SUPERSONIC AIR FLOW IN SAID NOZZLEAND MAINTAIN EXTREMELY HIGH AIR FLOW VELOCITIES SUBSTANTIALLY THROUGHOUTTHE ELONGATED SECTION OF SAID OUTLET TUBE, AND MANUALLY ACTUATABLEPNEUMATIC MEANS TO RAPIDLY AND SELECTIVELY VARY THE LONGITUDINALRELATIVE POSITIONS OF SAID OUTLET TUBE AND SAID AUXILIARY INLET TUBE INORDER TO VARY THE ANNULAR ORIFICE, THE IMPROVED DEVICE FURTHERCOMPRISING A BAFFLE MEANS COOPERATING WITH SAID ORIFICE FOR CREATING AZONE OF GREAT AGITATION IN THE AIR FLOWING THROUGH SAID NOZZLE AND SAIDOUTLET TUBE.